1. Technical Field
The present invention relates to a rolling piston type expansion machine most suitable for a Rankine cycle machinery.
2. Background Art
Generally, a Rankine cycle machinery performs an opposite operation to the cooling cycle. The Rankine cycle machinery is a heat engine where heat is obtained from a high-temperature heat source, and its part of the obtained heat is transformed to a work, so that excess heat therefrom is made low-temperature so as to be discharged. Thus the Rankine cycle machinery uses the work as a power source for compression. Outline of operation thereof is described as follows. High-pressure gas is supplied to an expansion chamber from a suction port, and power due to expansion work is generated so as to become low-pressure gas. Thereafter, the low-pressure gas, which completed the expansion work, is discharged from a discharge port. Timing at which the high-pressure gas is supplied to the expansion chamber, and timing at which the low-pressure gas is discharged are controlled by an open-close valve mechanism.
In the conventional expansion machine, there is necessitated the open-close valve in order to supply the high-pressure gas and discharge the low-pressure gas. Thereby, there are caused disadvantageous aspects in terms of assembly and installation of the open-close valve, and cost performance and increased amount of parts therefor.